Modified filament and fabrics produced therefrom



April 28, 1970 H.-R.-BA NALL L 7 90 MODIFIED FILAMENT AND FABRICS PRODUCED THEREFROM 1 Filed Sept. 30, 1968 FlG.l

I E I 0.7

0.5 (f/R) 0.4 U

F {3 c FIG 3 Q2 lv 0 O.| 0.2 0.3 0.4 (r IR) FIG. 2

1NVENTORS HARRY R. BAGNALL MAURICE S. MOORE ,JR.

THOMAS E. ADAMSON United States Patent Ofice 3,508,390- Patented Apr. 28, 1970 3,508,390 MODIFIED FILAMENT AND FABRICS PRODUCED THEREFROM Harry R. Bagnall, Norwalk, Conn., and Maurice S. Moore, Jr., Hopewell, Thomas E. Adamson, Richmond, and Forrest S. Wiggins, Chester, Va., assignors to Allied Chemical Company, New York, N.Y., a corporation of New York Filed Sept. 30, 1968, Ser. No. 763,859 Int. Cl. D02g 3/00 US. Cl. 57-140 26 Claims ABSTRACT OF THE DISCLOSURE A fine denier filament of a synthetic polymer having an essentially uniform cross-section along its length. The cross-section of the filament consists of three integrally joined, substantially symmetrical legs which form a substantially uniform Y-shaped cross-section. The cross-section has a tip radius ratio and a straight side ratio within the range represented by the area TUVW on FIGURE 2 of the drawing, and a modification ratio within the range from about 2.7 to about 5.0.

BACKGROUND OF THE INVENTION This invention relates to a synthetic filament. More particularly, this invention relates to a filament having a substantially uniform, Y-shaped cross-section prepared from synthetic polymers and fabrics prepared from the filament.

Filaments prepared from synthetic polymers, for example, from polyamides and polyesters, have a characteristic gloss or sheen which while being very desirable in certain products is undesirable in others. In many apparel fabrics as well as floor covering materials a subdued luster rather than a gloss or sheen is preferred. In addition, due to the somewhat transparent nature of such filaments, textiles prepared from them do not possess the degree of hiding or covering power required in certain fabric constructions.

Modification of the cross-section of a synthetic filament from its conventional, and often very useful, round cross-section to the less orthodox ellipse, crescent, star, or heart has become increasingly popular because of the property improvements such as appearance and feel thus imparted to the fabric. The novel filament of the present invention having a substantially uniform Y shaped crosssection is especially effective in adding, for example, to a nylon fabric produced therefrom, an attractive appearance which can be silky or wooly or anything between according to the garment features needed, and a dry hand which may be soft or crisp according to the designers desire. In addition, the novel filament of the present invention offers, for example, to a nylon fabric produced therefrom, the excellent dyeability and unsurpassed durability of nylon and, in addition, the novel features of a fabric having the appearance of fine silk, first quality cotton, or fabrics of other expensive synthetic filaments. These novel features can be accomplished through simple fabric construction and finishing techniques. Such novel features have never before been accomplished with modified cross-section fibers known to the prior art.

Furthermore, the novel filament of the present invention having a substantially uniform Y shaped cross section, in many cases, enables a textured fabric to be produced therefrom thus eliminating the need for expensive texturing of the fiber by mechanical deformations such as heat setting operations which include false twisting, stuffer box crimping, gear crimping, and the like.

In further addition, when the novel filament of the present invention having a substantially uniform Y shaped cross-section is subjected to the texturing operations as described above even more dramatic effects are achieved in fabric constructions which are not known to be achieved using prior art modified cross-section filaments under comparable processing conditions. For example, a greater degree of covering power, greater bulk and a higher degree of contrast and pattern definition are attained.

It has also been found that the synthetic filament having a substantially uniform Y shaped cross-section consisting of three integrally joined, substantially symmetrical legs exhibits outstanding and unique optical properties. These unique optical properties provide a high degree of cover and a pleasing subdued luster in fabrics.

SUMMARY OF THE INVENTION The legs of the filament of this invention are located with substantial symmetry about a central point. Each leg has a curved terminal portion or tip generated by a radius, the origin of which is along the line of symmetry of the leg. The curved terminal portions or tip of the leg is connected to adjacent tips by side portions which are essentially straight and which merge into curved portions which join the adjacent essentially straight side portions. The legs are further defined by a leg angle formed by extending a respective essentially straight side portion to intersection with the opposite respective essentially straight side portion.

In general, the filaments of this invention may be prepared by extruding molten polymer or a blend of polymers through a spinneret orifice which is Y shaped. Spinning conditions must, of course, be varied depending on the particular synthetic polymer being extruded. The conditions should be controlled to provide a filament having a substantially uniform cross-sectional shape along its length.

DETAILED DESCRIPTION OF THE INVENTION AND THE DRAWINGS The present invention will be more fully understood by reference to the following detailed description and accompanying drawing, in which:

FIGURE 1 is an enlarged representation of a crosssection of a filament of this invention;

FIGURE 2 is a graph showing the areas which define limits of the parameters of the cross-section of the filament of this invention; and

FIGURE 3 is an enlarged representation of a. spinneret orifice suitable for spinning the filament of this invention.

All of the cross-sectional shapes of filaments within the scope of the present invention can be defined by the following six parameters, the relationship of which are illustrated in FIGURE 1.

(1) The ratio of the tip radius r of the leg to the radius R of a circle a having a center C circumscribed about the tips b of the legs;

(2) The leg angle A formed by projecting the common tangents, that is, essentially straight sides d-e and d'-e' of each leg;

(3) The ratio of the length i of the essentially straight side d-e or the ratio of the length f of the essentially straight side d'-e' to the radius R of the circumscribed circle;

(4) The ratio of the radius r of the arc g to the radius R;

(5) The ratio of the radius R to the radius R of a circle having center C inscribed within the cross section, referred to herein as the modification ratio M.

(6) The angle A which defines are h formed by the radii r thereby forming tips b of the legs.

For convenience, we have chosen to define our invention in terms of relationships (1), (2), (3), (5), and (6), that is, the tip radius ratio r /R, the leg angle A, the essentially straight side ratio f/R, the modification ratio M, and the angle A which defines are 12 formed by the radii r thereby forming tips b of the legs.

In accordance with the present invention, the tip radius ratio r /R must be within the range from about 0.05 to 0.25, the leg angle A must be within the range from about that is, when the respective essentially straight sides are essentially parallel with each other to about 36, the modification ratio M must be within the range between about 2.7 to .0, the straight side ratio f/R must be within the range between about 0.28 to 0.8, and the angle A must be between 180 and about zero degrees.

It will be apparent by referring to FIGURE 2 that only certain combinations of the aforementioned parameters will provide the filaments having the outstanding properties of those of the present invention. Since a word definition of the parameters which define the special group of filaments of this invention would be quite lengthy and unduly complex, the filaments will be described by reference to FIGURE 2 of the drawings. In view of the fact that five parameters are used in defining the filament cross-sections, reference must be made to FIGURE 2. It should be noted that while the shape of the cross-section should remain within the limits set forth in FIGURE 1, slight variations in the parameters may occur along the length of the filament as well as from filament to filament in a bundle which do not adversely affect the novel properties of the filament. Accordingly, it is not required that the cross-sections exhibit perfect symmetry.

Referring now to FIGURE 2, the filaments must have a straight side ratio and a tip radius ratio within the range represented by the area TUVW, preferably within the range represented by the area ABCW, and most preferably within the range of curve D-E with an average deviation from this curve up to about i002 in the tip radius ratio r /R dimension. The area represented by the area TUVW must lie above the range of curve F-G. The modification ratio, as previously indicated, must be in the range from about 2.7 to 5.0

Filaments having a leg angle A between about 2 and 25 a tip radius ratio r /R between about 0.12 and 0.2, a straight side ratio f/R between about 0.4 and 0.6, a modification ratio M between about 2.8 and 3.3, and an angle A of less than about 170 are particularly preferred since this combination of the parameters provides textile materials having outstanding optical properties.

As previously indicated, spinning conditions used in preparing the novel products of this invention may vary, depending on the particular polymer being spun. In addition, the shape of the spinneret orifice may also be varied. An orifice having a Y shape as illustrated in FIGURE 3 may be used advantageously. The dimensions of the orifice can be adjusted to provide filaments of different crosssection and deniers. In general, deniers per filament from about 1 to about 35 can be used in many textile applications, however, even higher denier filaments can exhibit the aforementioned novel properties. The optimum denier will, of course, be dictated by the end use of the textile material to be prepared. In a most preferred embodiment, the filament of the present invention has great utility in line denier yarns, that is, for example, yarns up to about 40 denier, 12 filaments; 7O denier, 32 filaments; and even 200 denier, 64 filaments, from which knitted, woven, and non-woven fabrics can be prepared. In other words, the most preferred yarn of the present invention is a fine denier yarn having about 1 to 5 Or even up to about 10 denier per filament.

The filament-forming synthetic polymer can be a polyolefin, polysulfone, polyphenyl oxide, polycarbonate, polyacrylonitrile, polyamide, polyester and the like or polymer blends thereof. In a preferred embodiment of the present invention, the filament -forming synthetic polymer is a polyamide or a polyester.

Suitable polyamides for use in the present invention include, for example, those prepared by condensation of hexamethylene diamine and adipic acid, known as nylon 6,6 or by polymerization of e-caprolactam known as nylon 6.

The polyesters useful in the practice of this invention can be prepared in general by condensation reactions between dicarboxylic acids or their derivatives and compounds containing two hydroxyl groups, or materials possessing both an alcohol group and a carboxylic acid group or derivative thereof; or by the condensation-polymerization of lactones. Dicarboxylic acid derivatives which can be employed include esters, salts, anhydrides and acid halides. The monomeric species employed in the preparation of the polyesters are preferably not more highly functional than difunctional in their reactivity so as to produce essentially linear, non-crosslinked polymer structures.

Suitable polyesters for use in the present invention include those polymers in which one of the recurring units in the polyester chain is the diacylaromatic radical from terephthalic acid, isophthalic acid, S-t-butylisophthalic acid, a naphthalene dicarboxylic acid such as naphthalene 2,6 and 2,7 dicarboxylic acids, a diphenyl-dicarboxylic acid, a diphenyl ether dicarboxylic acid, a diphenyl alkylene dicarboxylic acid, a diphenyl sulphone dicarboxylic acid, an azo dibenzoic acid, a pyridine dicarboxylic acid, a quinoline dicarboxylic acid, and analogous aromatic species including the sulfonic acid analogues, diacyl radicals containing cyclopentane or cyclohexane rings between the acyl groups; and such radicals substituted in the ring, e.g., by alkyl or halo substituents.

The dioxy radical representing the other principal recurring unit in the polyester chain can be an open chain aliphatic such as ethylene glycol or ether thereof, for example, the diether, or can contain rings such as those which form part of the above noted diacyl radicals. The carboxy and/or the oxy chain members can be directly attached to a ring or removed by one or more carbons therefrom, as in the 1,4 dioxymethyl cyclohexane radical.

The preferred polyester is polyethylene terephthalate.

PREFERRED EMBODIMENTS The following examples illustrate the practice and principles of the present invention and a mode of carrying out the invention.

Example 1 Nylon 6 (polycaproamide) multifilament yarns were spun using the spinning conditions indicated in Table I below. Relative polymer viscosity of the polymers was determined at a concentration of 11 grams of polymer in 100 ml. of percent formic acid at 25 C. (ASTM D789-62T) and is indicated in Table I. The molten polymer was extruded at the temperatures indicated in Table I through spinneret orifices with the specific dimensions indicated in Table I. The spinneret used in samples A, B, and E had 12. holes and produced yarns with 12 filaments. The spinnerets used in samples C, F and D, G were 2 spinnerets having 16 holes each, and 4 spinnerets having 16 holes each, respectively, and produced yarns with 32 and 64 filaments, respectively. Samples A, B, C, and -D were spun through orifices of the type shown in FIGURE 3 with the dimensions indicated in Table I. Samples E, F and G were spun through round orifices.

The molten filaments solidified as they passed down ward through a quench zone of moving air, and the yarns were wound up on sleeves. After spinning, the yarns were drawn at the draw ratios indicated in Table I, where draw ratio indicates the ratio of speed of the delivery roll to the speed of the feed roll.

The cross-sectional configurations of the filaments in each of the samples depends on the configurations of the spinneret orifices. The average measurements of the cross sectional parameters for each of the samples is indicated in Table I below.

TABLE I Sample Number A B C D E F G Relative viscosity of polymer 58 58 58 58 58 58 58 rfi yp Leg dimensions,

inches:

Length of leg from tip to center 0.050 0.050 0.030 0.030 Width of leg 0.0045 0.0045 0.003 0.003 Quench air rate (ftfi/ m 85 100 100 85 85 80 Takeup speed (meters/ min.) 900 1,150 1,050 900 800 800 600 Draw ratio 1.99 2.32 2.44 2. 78 3.33 3.33 3.60 Yarn denier (drawn). 40 40 70 200 40 70 200 Number of filaments. 12 12 32 64 12 32 64 Cross-sectional measurements:

4.5 3.0 3.1 0.13 0.13 0.20 0.70 0.50 0.59 Melt spinning temperature.C 250 268 270 31egs. 2 Round.

Example 2 The 40 denier yarns B and E of Example 1 containing a /2 Z twist were warp knitted on a conventional 2 bar 28 gauge tricot knitting machine into jersey fabrics. The runner of the bottom beam was 49 inches and the runner of the top beam was 63 /2 inches. The fabrics were then finished in a conventional manner and printed. The jersey fabric produced from the novel 40 denier Y cross-section yarn B of the present invention had a textured hand and a textured appearance, a high degree of cover, a high degree of print definition, and a desirable silky hand whereas the jersey fabric produced from the 40 denier conventional round cross-section yarn E had a non-textured soapy hand and a non-textured appearance which is usually associated with the conventional round and modified cross-section nylon filament yarns, less cover and less print definition.

The 40 denier yarn E having a round cross-section of Example 1 containing a /2 Z twist was textured on standard false twist texturing equipment that is commonly used in the throwing trade. The textured yarn was then warp knitted on a conventional 2 bar 28 gauge tricot knitting machine into a jersey fabric under similar knitting conditions as used above. The fabric was then finished in a conventional manner and printed. The fabric produced from the textured 40 denier conventional round crosssection yarn E had a textured hand and a textured appearance, good cover, good print definition, and a desirable silky hand. The fabric produced from the novel 40 denier Y cross-section non-textured yarn B of the present invention was comparable in all respects to the fabric produced from the textured 40 denier conventional round cross section yarn E. This example illustrates that the novel Y cross-section filament yarn of the present invention produces a fabric having a textured hand and textured appearance without the need of an expensive yarn textur ing operation.

The physical properties of the fabrics are contained in Table II below.

TABLE II Knitted Knitted Control Knitted Control Physical Property Fabric Fabric Fabric Yield:

Sq. yd./lb. of fabric 6. 58 6. 58 6. Oz./sq yd of fabric 2. 43 2. 43 2. 94 Thickness, mils -7 10 12 14 cu. ft. of air min. Air permeability, m 609. 5 552 455 Contact covering power 6 79.1 81. 6 82. 6

. contac covering power Opacity, ozlsql Yd' of fabric 32. 5 33.6 28.1 Moisture absorbancy, percent moisture absorbed 61. 7 84. 7 99. 2 Weight of equivalent package volumes, lbs. yarn E v. yarn B-.- 3. 00 2. 43

1 Containing the non-textured round cross-section yarn E.

2 Containing the non-textured novel Y cross-section filament yarn B of the present invention.

3 Containing the textured round cross-section yarn E.

ASTM 737-66 Part 24 (1966).

5 Percent reflectance on black background) Percent reflectance on white background When the value is 100, the fabric is opaque; when the value is 0. the fabric is transparent.

5 The fabric was washed at F. in a 0.5 wt. percent neutral soap solution which contained 0.2 wt. percent NazCOa for 15 min. followed by two rinses of 10 and 15 min. each at 160 F. Five 3 x 3in. samples were weighed after conditioning for 4 hrs. at 65 percent relative humidity at 70 F. The samples were then immersed in tap water at 80F. for 2 min. The samples were withdrawn from the tap water, drained for 10 sec. and then Weighed.

. con 1 ione weig Nora. Wt. percent moisture absorbed conditioned weight) 100. Example 3 The 40 denier yarn B of Example 1 containing a /2 Z twist and a conventional round cross-section 30 denier, 6 filament nylon 6 yarn containing /2 Z twist (30 6 /2 Z) were warp knitted on a conventional 2 bar 28 gauge tricot knitting machine into a modified jersey fabric. The bottom beam contained the novel Y cross-section filament yarn B of the present invention and the top beam contained conventional round cross-section yarn. The front bar was knitting 3,4/ 1,0 and the back bar was knitting 1,0/ 1,2. The runner at the bottom beam was 58 inches and the runner of the top beam was 71 /2 inches. The fabric was then finished in a conventional manner and printed. A modified jersey fabric was also produced under the above conditions using the conventional round crosssection yarn E in place of the novel Y cross-section filament yarn of the present invention.

The modified jersey fabric produced using the novel 40 denier Y cross-section filament yarn B of the present invention in only one of the two beams had a textured hand and a textured appearance, a high degree of cover, a high degree of print definition, and a desirable silky hand whereas the modified jersey fabric produced from the 40 denier conventional round cross-section filament yarn E and the 306 /2 Z nylon 6 yarn had a non-textured, soapy hand and a non-textured appearance, which is usually associated with the conventional round and modified crosssection nylon filament yarns, less cover and less print definition. This example illustrates that the presence of only one bar of the novel Y cross-section filament yarn of the present invention in a two bar fabric will produce a desirable fabric having a textured hand and textured appearance without the need of an expensive yarn texturing operation.

The physical properties of the fabrics are contained in Table III below.

TABLE III K d o t Physical Property Fab riii Fa br i Z Yieli: d In If q. y o abric 7. 21 7. 27 Oz./sq. yd. of fabric 2. 22 2. 2 Thickness, mils- 11 11 cu. ft. of air min. Alr permeability, it. of fabric 4 582 438 Contact covering power 5 74. 2 76. 5

contact covering power opcm oz. sq. yd. of fabric 4 8 Moisture absorbency, percent moisture absorbed B 194 195. 7 Weight of equivalent package volume, lbs.

yarn E v. yarn B 3. 00 2. 43

7 Example 4 The 40 denier yarn B of Example 1 containing /2 Z twist, a 2 ply, 20 denier, monofilament nylon 6 yarn having zero twist (2-20-1-00) and a single ply, 20 denier, monofilament nylon 6 yarn having zero twist (20-1-00) were warp knitted on a conventional 3 bar 28 gauge tricot knitting machine into a 3 bar, novelty tricot fabric. The bottom beam contained the 2-20-1-00 nylon 6 yarn, the middle beam contained the novel Y crosssection filament yarn B of the present invention and the top beam contained the 20-1-00 nylon 6 yarn. The 2-20-1-00 nylon 6 yarn was threaded solid in the back bar. The front bar was knitting 0,1/2,1, the middle bar was knitting '0,1/3,2, and the back bar was knitting l,2/ 1,0. The runner of the bottom beam was 42 inches, the runner of the middle beam was 92 inches, and the runner of the top beam was 54 /2 inches. The fabric was then finished in a conventional manner. A 3 bar novelty tricot fabric was also produced under the above conditions using the conventional round cross-section filament yarn E of Example 1 in place of the novel Y crosssection filament yarn B of the present invention.

The 3 bar, novelty tricot fabric produced using the novel 40 denier Y cross-section filament yarn B of the present invention had a napped, textured appearance and hand, high degree of cover, a warm, desirable hand and a high degree of opacity whereas the 3 bar, novelty tricot fabric produced using the 40 denier conventional round cross-section filament yarn E had a lesser degree of nap, textured appearance and hand, less cover, less opacity, and a soapy hand usually associated with the conventional round and modified cross-section nylon filament yarns. This example illustrates that the novel Y cross-section filament yarn of the present invention produces a fabric having a napped, textured appearance and hand without the need of an expensive fabric napping operation.

The physical properties of the fabrics are contained in Table IV below.

TABLE IV Knitted Control Knitted Physical Property Fabric 1 Fabric leld:

Sq. ydJlb. of fabric 4. 97 5. 13 Oz./sq. yd. of fabric 3. 22 3. 12 Thickness, mils. fE.. t. i 25 30 cu. o a r m 11. Air permeability, m 295 183 Contact coveirintg poweir 87. 90. 2

con ac cover ng power Opacity oz./sq. yd. of fabric 0 9 Moisture absorbancy, percent moisture absorbed 182. 201. 6 Weight of equivalent package volumes, lbs.

yarn E v. yarn B 3. 00 2. 43

See footnotes at end of Table II:

Example 5 The 40 denier yarn B of example 1 containing /2 Z twist and a 2 ply, 40 denier, 12 filament deep dye nylon 6 containing Z twist (2-40-12- /z Z) were warp knitted on a conventional 2 bar 28 gauge tricot knitting machine into a 2 bar stabilized stitch tricot fabric. The bottom beam contained the novel Y cross-section filament yarn B of the present invention and the top beam contained the novel Y cross-section filament yarn B of the present invention and the 2-40-12- /2 Z deep dye nylon 6 yarn. The back bar was threaded solid with the 40 denier yarn B of Example 1. The front bar was threaded as follows: one end 40 denier yarn B, one end 2-40- 12 /2 Z deep dye nylon 6 yarn, one end 40 denier yarn B, one end out. The front bar was knitting 0,1/ 1,0 and the back bar was knitting 3,4/ 1,0. The runner of the bottom beam was 80 inches and the runner of the top beam was 40 inches. The fabric was then finished and dyed in a conventional manner. A 2 bar stabilized stitch tricot fabric was also produced under the above conditions using the 40 denier conventional round cross-section yarn E of Example 1 in place of the novel Y crosssection filament yarn of the present invention.

The 2 bar stabilized stitch tricot fabric produced using the novel 40 denier Y cross-section filament yarn B of the present invention had a desirable cotton hand as usually associated with shirting which can also be described as a masculine hand, a high degree of opacity, a high degree of bulk, good drape and shape retention. This novel fabric retained the desirable nylon characteristics which include strength, ease of care in laundering, and wear resistance in addition to the above mentioned desirable properties. The 2 bar stabilized stitch tricot fabric produced using the 40 denier conventional round cross-section filament yarn E had an undesirable slick hand, low opacity, poor drape characteristics, that is, it overdraped, and a soapy hand usually associated with the conventional round and modified cross-section nylon filament yarns. This example illustrates that the novel cross-section filament yarn of the present invention produces a fabric having a desirable cotton hand as usually associated with shirting and which has never before been accomplished with a nylon yarn.

The physical properties of the fabrics are contained in Table V below.

Knitted Control Knitted Physical Property Fabric 1 Fabric 3 Yield:

Sq. yd./lb. of fabric 6. 72 6. 9 Oz./sq. yd of fabric 2. 38 2. 29 Thickness, mills ..i.. 9 11 cu. it 0 air rmn Air peimeabihty, Sq ft of fabric 323 281 Contact covering power 5 82.6 88. 4

. contact covering power p y, (mi/Sq yd of fabric 7 6 Moisture absorbency, percent moisture absorbed 5 130. 6 217 Weight of equivalent package volumes, lbs.

yarn E v. yarn B 3. 00 2. 43

See footnotes at end of Table II.

A shirt was manufactured from the 2 bar stabilized stitch tricot fabric produced using the novel 40 denier Y cross-section filament yarn B of the present invention. The shirt was of a comparable quality to that of one produced from cotton shirting fabric.

Example 6 The 40 denier yarn B of Example 1 containing /2 Z twist, a 15 denier monofilament nylon 6 yarn having zero twist (15-1-00) and a 30 denier, 6 filament nylon 6 yarn containing /2 Z twist (30-6- /2 Z) were warp knitted on a conventional 3 bar 28 gauge tricot knitting machine into a 3 bar novelty tricot fabric. The bottom beam contained the 30-6- /z Z nylon 6 yarn, the middle beam contained the novel Y cross-section filament yarn B of the present invention and the top beam contained the 15-1-00 nylon 6 yarn. The novel 40 denier Y crosssection filament yarn B of the present invention was threaded solid in both the back and middle bars. The front bar was knitting 1,2/ 1,0, the middle bar was knitting 0,1/ 3,2, and the back bar was knitting 0,0/2,2. The runner of the bottom beam was 19 /2 inches, the runner of the middle beam was 82 inches, and the runner of the top beam was 47 /2 inches. The fabric was then finished in a conventional manner. A 3 bar, novelty tricot fabric was also produced under the above conditions using the conventional round cross-section filament yarn E of Example 1 in place of the novel Y cross-section filament yarn B of the present invention.

The 3 bar, novelty tricot fabric produced using the novel 40 denier Y cross-section filament yarn B of the present invention was a creped fabric having a textured appearance and hand which resembled a soft, wool-like crepe. The fabric had a high degree of cover, a high degree of bulk, a soft, wool-like hand, good fabric drape, resiliency and adequate cover whereas the 3 bar, novelty tricot fabric produced using the conventional round crosssection filament yarn E had poor opacity, poor resilience and inadequate cover and was of a distorted knit fabric structure which did not have enough bulk to hide the construction.

This example illustrates that the novel novel cross-section filament yarn of the present invention produces a creped fabric having a textured appearance and hand which resembles a soft wool-like crepe without the need for the application of an expensive creping operation to the fabric.

The physical properties of the fabrics are contained in Table VI below:

TABLE VI Knitted Control Knitted Physical Property Fabric 1 Fabric 2 Yield:

Sq. yd/lb. of fabric 5. 46 5. 5 Oz./sq. yd. of fabric 2. 93 2. 9 Thickness, mils t f l 17 20 cu.f air nn'n. All permeability, 380 238 Contact coverintg power 89. 9 92. 0

con ac covering power Opamty' oz./sq. yd. of fabric 7 Moisture absorbancy, percent moisture absorbed 6 125. 3 221 Weight of equivalent package volumes, lbs.

yarn E v. yarn B 3.00 2. 43

See footnotes at end of Table II.

Example 7 The 70 denier yarn C and F of Example 1 containing a Z twist were textured on standard stufr'er tube texturing equipment that is commonly used in the throwing trade. The 2 plied textured yarns were then circular knitted into a fabric having a blister stitch on an 18 cut Bentley double knit circular knitting machine. The fabrics were then dyed and finished. The fabric produced from the novel textured 70 denier Y cross-section filament yarn C of the present invention was found to have a high degree of bulk, a great degree of pattern definition, a dry, more crisp hand, a high degree of cover and a different and pleasing luster whereas the fabric produced from the textured conventional 70 denier round crosssection yarn F had less bulk, less pattern definition, a less dry and crisp hand and less cover.

The physical properties of the fabrics are contained in Table VII below.

1 Containing the textured round cross-section yarn E.

2 Containing the textured novel Y cross-section filament yarn B of the present invention.

3 AS'IM 737-66 Part 24 (1966).

4 The fabric was washed at 160 F. in a 0.5 wt. percent neutral soap solution which contained 0.2 wt. percent NazCOa for 15 min. followed by two rinses of and 5 min. each at 160 F. Five 3 x 3 in. samples were weighed after conditioning for 4 hrs. at 65 percent relative humidity at 70 F. The samples were then immersed in tap Water at 80 F. for 2 min. The samples were withdrawn from the tap water, drained for 10 sec. and then weighed.

Example 8 The 200 denier yarns D, and G of Example 1 containing a /2 Z twist were textured on standard false twist texturing equipment that is commonly used in the throwing trade. The textured yarns were then circular knitted into a fabric having a blister stitch on an 18 cut Bentley double knit circular knitting machine. The fabrics were then dyed and finished. The fabric produced from the novel textured 200 denier Y cross-section yarn D of the present invention was found to have a high degree of bulk, a great degree of pattern definition, a dry, more crisp hand, a higher degree of cover, and a different and pleasing luster whereas the fabric produced from the textured 200 denier conventional round crosssection yarn G had less bulk, less pattern definition, a less dry and crisp hand and less cover.

The physical properties of the fabrics are contained in Table VIII below.

The 40 denier yarn A of Example 1 containing 5 /2 Z twist was woven into a plain weave fabric having 153 yarns per inch in the warp and 109 yarns per inch in the fill. The fabric produced from the novel 40 denier yarn A (4.5 modification ratio) of the present invention had a high degree of bulk, a dry, crisp hand, and a high degree of cover.

Examples 7 and 8 illustrate that even more dramatic effects are achieved in fabric constructions when the novel Y cross-section yarn of the present invention is subjected to a texturing operation. It should be understood that the present invention is not limited to the specific texturing operations as described in Examples 7 and 8 and that other texturing operations such as gear crimping, air jet crimping, knife edge crimping and the like are within the scope of the present invention.

It is claimed:

1. A fine denier filament of a synthetic polymer having an essentially uniform cross-section along its length, said cross section consisting of three integrally joined, substantially symmetrical legs thereby forming a substantially uniform Y shaped cross-section said crosssection having a tip radius ratio and a straight side ratio within the range represented by the area TUVW on FIGURE 2 of the drawing, and a modification ratio within the range from about 2.7 to about 5.0.

2. The filament of claim 1 wherein the tip radius ratio is within the range from about 0.12 and about 0.2.

3. The filament of claim 1 wherein the straight side ratio is within the range from about 0.4 to about 0.6.

4. The filament of claim 1 wherein the modification ratio is within the range from about 2.8 to about 3.3.

5. The filament of claim 1 wherein the tip radius ratio and the straight side ratio are within the range represented by the area ABCW on FIGURE 2 of the drawing.

6. The filament of claim 5 wherein the tip radius ratio and the straight side ratio are within the range of curve D-E on FIGURE 2 of the drawing with an average deviation from this curve up to about 1:002 in the tip radius ratio dimension.

7. The filament of claim 1 wherein the synthetic polymer is polyamide.

8. The filament of claim 7 wherein the polyamide is nylon 6.

9. The filament of claim 1 wherein the synthetic polymer is polyester.

10. The filament of claim 9 wherein the polyester is polyethylene terephthalate.

1-1. A textile yarn comprised of filaments of claim 1.

12. The yarn of claim 11 wherein the yarn is a fine denier yarn of up to about 200 denier.

13. The filament of claim 1 wherein the tip radius ratio is within the range from about 0.12 and about 0.2, the straight side ratio is within the range from about 0.4 to about 0.6, and the modification ratio is within the range from about 2.8 to about 3.3.

14. A textile yarn comprised of filaments of claim 13.

15. The yarn of claim 14 wherein the yarn is a fine denier yarn of up to about 200 denier.

16. A knitted fabric prepared from the yarn of claim 11.

17. A woven fabric prepared from the yarn of claim 11.

18. A non-woven fabric prepared from the yarn of claim 11.

19. A knitted fabric prepared from the yarn of claim 11 having a textured hand and a textured appearance, a high degree of cover, a high degree of print definition, and a desirable silky hand.

20. A knitted fabric prepared from the yarn of claim 11 having a napped, textured appearance and hand, a high degree of cover, a high degree of opacity, and a warm desirable hand.

21. A knitted fabric prepared from the yam of claim 11 having a desirable cotton hand, a high degree of bulk, a high degree of opacity, good drape and shape retention.

22. A shirt manufactured from the fabric of claim 16.

23. A knitted fabric prepared from the yarn of claim 11 which has the appearance of a creped fabric having a textured appearance and hand which resembles a soft, wool-like crepe, a high degree of cover, a high degree of bulk, a soft wool-like hand, good fabric drape, resiliency and adequate cover.

24. A woven fabric prepared from the yarn of claim 11 having a high degree of bulk, a dry, crisp hand, and a high degree of cover.

25. The yarn of claim 11 wherein the yarn has been subjected to a texturing operation and is a textured yarn.

26. A knitted fabric prepared from the yarn of claim 25 having a high degree of bulk, a high degree of pattern definition, a dry crisp hand, a high degree of cover.

References Cited UNITED STATES PATENTS 2,637,893 5/1953 Shaw. 2,939,201 6/1960 Holland 57l40 XR 2,939,202 6/1960 Holland 57--140 3,097,416 7/1963 McKinney 57-140 3,121,040 2/1964 Shaw et al. 161-177 DONALD E. WATKINS, Primary Examiner US. Cl. X.-R. 

